Manufacture of electric filaments.



G. A. VON WBLSBAUH.

MANUFACTURE OF ELECTRIC PILAMENTS.

APPLICATION FILED AUG. 9, 1898.

Patented Nov. 22,1910.

lyu/erdon UNITED s A'rEs mm onnron.

CARL AUER VON WELSBACH, OF VIENNA, -AU S"TRIA-HUNGARY, ASSIGNGB TO 'WELS' BACH LIGHT COMPANY, OF GLOUCESTER CITY, NEW JERSEY, A CORPOlEt-ATION OF NEW JERSEY.

MANUFACTURE-'01! nnncrnxo FrLAMENTs.

1898lSeria1 1io.688,2 04.

.To all whom it may concern:

gar-y, have invented or discovered a" certain new and useful Improvementin'the' Mannfacture of Electric Filaments, of which the,

' leadingdnwires and the finished filamentis inserted in the bulb the cementjoi nt' is slightly warmed, access of air not-interfer v following is a specification.

My invention relates to the manufacture of incandescent electric lamps and has for its object principally to unite an osmium filament or a filament containing osmium or its alloys with the leading-1n wires of M11111; candescent electric light bulb.

The invention is conventionally illustrated in the. single figure of the accompanying drawing.

in. other applications for Letters Patent of the United States of even date herewith, I h ave described an incandescent electric light filament whereimduring the course of manuiacture the filamentary body in a preliminary stage of its reparation consists of osmium,

v or osmium a loy with or without certain 1e fractory rare earths in the presence of a carbonaceousc'arrier orbinder, as, for in-v stance, a carbonaceous thread or a'carbo naceous agglutinant; The carbonaceous'car rier or binder'referred to, after the filamentary body has been dried, is brought into the form required for the ultimate filament and is then slightly heated in a reducing atmosphere. The resulting carbon skeleton imparts to the filament as u whole, increased strength, elasticity and conductivity for its subsequent treatment, which consists in placing the filament in a chamber filled with suitable reducing gases together with apors of water, when "on heating the filament elec-v trically the carbon is elimmated and the filament is: then ready for inserting in'the' lead: ing in wires of the bulb as follows: The free ends of'the customary platinum leading-in wires are formed for the reception of the corresponding ends of the filament whereupon the points of juncture are covered'with or embedded in a small quantit or the-ce' ment consisting of finely divide osmium or an osmium compound to which maybe added a small quantity of the salt or saltsof the other platinum metals such as ruthenium or rhodium, or of these metals or their alloys with a smallquantity of a binding material such as sugar and water suificient to bring it to acreamy paste-like consistency. But.

when the filament is one of osmium I have Patented Nov. 2.2, 191d. 7

foundthat the cement must likewise be of metallic base of the cement may be the same asthat of the filament,

Before the plug which bears the p1iumitfl,

ing with the action. It is thenlplacedin the bulb filled with a dry reducing gas andl au-I 'ing been ut into an electric circuit andthc, filament. rought' to lncandescence the on ganic matter of the binding mo terial of the l cement is eliminated and its metalllc ticles rendered dense and coherenhend'pan tially fused or welded to the filament and caused to, adhere to the lcadin'gdn vwires which platinum wouldfuse; to

As the temperature at which the {filament lwillincandesce is beyond t'l'iatatwhi'ch the platinum oi the leading in wires would fuseor alloy with the filament, obviously the be :mentiing medium must be such as will withstand the-sametemperature asithat. of. the filament and yet so'reduce the temperature at thepoint of juncture with the platinum as to oreventits fusion, and this I do by the 1. '90

use oi a paste the metallio'base ofwhich is the same as that of thefilament aml'whi'ch when applied will at the point oil-juncture. increase the cross section of the filament-at that point the effect of ,which is to there;

reduce the electrical ,resistancelgreatly reducing, the temperature produced at the p'ointof contact between the platinum. and,

the metal of 'thecernenting or welding, 11in terial.

filament thatincandesces at a temperature at which -platir lum would lose in; an incan:

descent electric lamp,which so fer-as I know has not before been accomplished, and thus I am enabled to, electricallyconnect or weld together in an incandescent lamp a filament which incandesces at a temperature above that at which the leading in wires would fuse, and thus make possible the production of an incandescent electric light provided with an osmium filament.

Instead of eliminating the organic matter of the binding material after the filament has been placed in the bulb it may be eliminated prior thereto in the presence of a suitable reducing gas containing Water vapor and under theaction of the electric current; in either case after the filament has been placed in the bulb and the organic matter of the binding material has been eliminated, the filament must then be'brought to incandescence in the presence of a dry reducing gas and while in that condition the bulb is exhausted and sealed as in the ordinary manner.

My so called osmium cement may also be used in' a like manner during the manufacture of the filament as for instance in securing it into the holder used during the process of its manufacture; it may also be used for joining or welding together broken filaments as well as for strengthening filaments at weak points.

I have hereinbefore referred to the employment of a suitable reducing gas containing water vapor as one of the accessories for carrying out to advantage the purposes of the present invention. Such a reducing gas containing water vapor is presented, for instance in the gases issuing from the burner tube of the struck back flame of a Bunsen burner, z'. e., of a Bunsen burner wherein the gas is ignited at the air inlet openings. Such a gas contains carbonic oxid, carbonic dioxid, hydrocarbon gases, and watery vapor, and has the property of removing the carbon, without oxidizing the osmium present.

Having thus described my invention what I claim is:

1. An incandescent electric lamp having its filament connected to its leading-in-wires by a connecting body of osmium.

2. An incandescent electric lamp having a filament containing osmium connected to the leading-in wires by an osmium connection.

3. An incandescent electric lamp having a filament containing osmium, platinum leading-in wires, and an osmium connection connecting the filament with the leading-in wires.

4. An incandescent electric lam having leading-in wires whose ends are ashioned for the reception of the ends of the filament, a filament mounted therein and an-osmium joint at thepoints of juncture.

'5. The process of -mounti ng filaments,

which consists in connecting the endsof the filaments to the ends of leading-in wires by a cement paste containing osmiuinand a carbonaceous agglutinant, warming the paste in order to obtain an initial adherence at the point of juncture, and finally removing the carbon of the aste without oxidizing the osmium by su jecting the paste to heat in the presence of reducing gases containing vapor of water.

6. An incandescent electric lamp having a metallic filament connected to its leadingin wires by a body or bodies the metallic base'of which is substantially the same as the metallic base of the filament.

7.-An incandescent electric lamp, having a metallic filament, and leading-in wires, the incandescing temperature of the filament being beyond that at which the metal of the leading-in wires would fuse, and a connecting metallic fuse-joint uniting the filament and leading-in wires, the metal of the fusejoint being substantially the-same as the metal of the filament.

8. The process of connecting to the leading-in wires of an incandescent lamp, a metallic filament whose temperature of in candescence is. beyond that at which the metal of the leading-in wires would fuse, which consists in interposing at the juncture of the leading-in wires with the ends of the metallic filament a mounting whose fusing point is sufiicient to withstand the temperature of the filament and protect the metal of the leading-in wires from fusing or alloying with the filament, and passing a welding current through the leading-in wires, mounting and filament, thereby completing the joint.

9. 1he process of welding the metallic filament of an incandescent electric lamp with its leading-in wires, where the incandescin temperature of the filament. is beyondt at at which the metal of the leading in wires would fuse, through the medium of. a mountin the metallic base of which is substantial y that of the filament, applied at the juncture between the ends of the filament and the leading-in wires so as to increase thecross section of the ends of the filament at those points thereby reducing the resistance and consequently the temperature at the point of Contact ofth'e loading-in wires with the connecting medium.

Si ed this 27th da of July 1898.

ARL AUER. ON WVELSBACR. Witnesses:

Lunwro HAITINGE, ADOLF Gum. 

